System of motor control.



No. 830,242. PATENTED SEPT. 4, 1906. A. MAGNUSON.

SYSTEM OF MOTOR CONTROL.

APPLICATION FILED SEPT. 20. 1905.

g Q S WITNESSES: W%)VENTOR 6. BY I m ATTORNEY UNITED STATES PATENTOFFICE.

AXEL MAGNUSON, OF NEW YORK, N. Y., ASSIGNOR.TO OTIS ELEVATOR COMPANY, OFJERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Sept. 4, 1906.

Application filed September 20, 1805. Serial No. 279,367.

To all whom it may concern:

Be it known that I, AXEL .MAGNUSON, a citizen of the United States, anda resident oi New York city, in the county of New York and State or NewYork, have invented certain new and useful Improvements in S sterns ofMotor Control, of which the following is a specification.

My invention relates to a system of motor control and it consists of anovel arrangement of various apparatus and circuits Whereby an electricmotor may be started, stopped, and otherwise controlled at will.

Although my system is applicable to other types of electric motors, itmay be used to great advantage in conjunction with such motors as areoperated by alternating currents.

I have made application for Letters Patent, Serial No. 241,592, filedJanuary 18, 1905, for a system of motor control whic embodies the broadideaof the present invention,

and the present invention is of certain improvements and developments ofthe inven tion disclosed in said prior application.

Referring to the drawings, Figure 1 shows in side elevation anelectricmotor and certain other apparatus which I use in carrying out myinvention, together with a diagrammatic representation of theirconnecting electrical circuits. Fig. 2 shows a modification of' one partof my invention- Like'characters of reference designate cor respondingparts in both of the figures.

designates an electric motor which is to be controlled. It is shown as amultiphase alternating-current motor; but it may be of any other desiredtype. designates a direct-current generator of the series-wound type. Itis connected to run with the motor and to be driven thereby. It may bedirectly connected to the motor by having its shaft 21 connected to themotor-shaft 11 by a coupling 22, as shown, or it may be connected in anyother suitable manner.

30 designates a transformer. Its primary may be connected to a suitablesource of electrical supply. Its secondary may be connected by the mains31, 32, and 33 through a manually-operated mainline switch 34 to thevarious parts of the apparatus, as will be shown latter.

50 designates a circuit-closer for the motorcircuits which may beoperated mechanically or electrically and which constitutes astarting-switch .or a reversmg-switch for the mo- 1- to the left ontocontact-plate 82, a circuitis I completed thereb from main-dineconductor 31', through con uctor 32, pivoted arm 81, stationary contact82, conductor 84, winding 61 of magnet 60, and conductor 33", to main33. The magnet-winding 61 will therefore be connected across mains 31and 33, and magnet will be energized thereby. This magnet comprises aframe 62, which is preferably constructed of laminated magneticmaterial, and a core 63 of similar material. When it is energized, itwill lift this core and certain connected parts which I will now pointout.

Directly below magnet 60 are certain stationary contacts, two of whichare designated by 64 and 64 Two movable contacts 65 and 65 are mountedupon, but insulated from, a cross-bar 68, whlch is connected to core 63by a rod 63. When core 63 is raised, these movable .contacts 65* 65 arebrought up against the stationary contacts 64 64,

respectively, and thereby close certain motor-circuits. By inspectingthe diagram it may be seen that main-line conductor 31 is connected tostationary contact 64 and that main-line conductor 33 is connected tostationary contact 64. It may also be seen that motorterminal 12 isconnected to movable contact 65 by conductor 12 and that motor-terminal14 is connected to movable contact 65 by conductor 14*, while themainline conductor 32 is directly connected to the centralmotor-terminals 13. Now when magnet 60 has been energized and has closedits contacts, it is evident that the mains 31, 32, and 33 will then beconnected to motor-terminals 12, 13, and 14, respectively. The motorwill then begin to rotate in one direction. When the operator brings thepivoted contactlever 81 of switch back to its central posi- 80 is amanually-operated switch which i tion, this will break thecircuitthroughmagnet-winding 61, and magnet-60 will be deenergi'zed and willallow its core to drop. This ceive current from the line in the o positedirection from that before describe and will begin to rotate in theopposite direction.

I sometimes arrange to o erate the revers- I ing-switch 50 by hand, anfor this purpose When the vertical the three-armed lever 51 may beprovided. This is pivoted at 54, and the ends of its horizontal positionmay be connected, as shown, by rods 52 and 53 to magnet-cores 63 and 73and through the latter to the movable con-' tacts below the magnets.

The, operation of this device is obvious.

moved to the right, t e contacts under magnet 60 will be closed. When itis moved to the left, the switch underma net 70 will be closed and whenit is brought ackto central positionall this switch will be opened. Thusthe motor may be started by manual means infieither direction or itmaybe stopped at wi An opposition element 90 may be included in themotor-circuit to prevent its too-rapidv acceleration. I have shown" suchan element at 90 in the form of a deltaconnected resistance. This isshown connected inthe rotor of motor 10 by conductors 91, 92, and 93. Itis desirable to gradually cut this resistance out of the rotor-circuitautomatically as the motor accelerates, andit is also desirable thatthis should be done in proportion to the accel- I eration ofthe motor,which will vary with different loads. v

I will now briefly describe an arrangement which '1 have invented foraccomplishing the above results. 7 v

20 is a direct-current generator, which, as

' has been stated, is connected to runwith the motor. quently itsgenerated voltage, will be proportional to the s eed of the motor. Thismay have a series eld 23, one side of which is connected to stationarycontacts and of the reversing-switch 50 by conductor 237, and

the other side of which ma lead to other devices by conductor 24. i woother stationary contacts of the reveising-switchare connected togetherand to certain other apparatus by conductor 25. The armature 26 may beconnected to the movable contacts, as.

shown, in such a manner as to reverse the This would have connectedmains 31 ortion of 'lever 51 is generator 20, as shown.

Therefore .its speed, and conse-.

connections on the reversingswitch between the armature 26 and theseries field 23. This will cause the generated current to ass always inone direction through series elds 23 and the mains 24 and 25. Themagnetic fields of generator 20 will therefore beenergiz'ed quickly anda current willbe generated a quickly.

The generated current will be approximately proportional in strength tothe speed of the motor, and it is this variable strength of generatedcurrent which I utilize to auto- .inatically control the acceleration ofthe motor and to perform certain other functions.

designates an electroresponsive device which comprises a solenoid-coil101 within a ma net-frame 102, arran ed when energized "to lift a core103, to whic 'is attached a sliding contact 104.-v The frame and coreare preferably constructed of laminated magnetic material. ranged to begradually drawn up over a se ries of stationary contacts 105. These maybe connected to the resistance 90, as shown,

and so arranged that as sliding contact 104 is drawn over stationarycontacts 105 it short? circuits resistance 90 in a number of steps.

Sliding contact 104 is ar- Solenoid-coil 101'may be'directly connect- It ed to the leads or mains 24 and 25 from generator 20, as shown, sothat its'energization and consequently the action of the core 103 andcontact 104 will be proportional to the voltage of generator 20. Isometimes connect a dash-pot with core 103 to further regulate itsmovement. This maybe done in a well-known manner, which needs no furtherdescription here.

desi nates an electrically-actuated brake, whic may be arranged to actuponv some moving part of the motor or its connected mechanismas, forexample, upon the coupling 22. within a magnet-frame 112 and a magneticcore 113, which is connected to a brake-shoe 114 by a rod 115. This ismerely a diagram-' matic construction for the purpose of illus-y'tratii'i my invention; but in practice many other orms of constructionma be used, if .desired. The winding 111 may e cpnnected directly to themains or leads 24 25 from the gized by.a variable current which will in=It comprises a winding 111 Itwill then be ener-' I crease in strength asthe speed of the motor 10 increases. When the magnet is sufiicientlyenergized, it will exert an u ward ull upon core 113 and willapply therake 3 0e 114 to the coupling or brake-pulley 22. The effect of thisbrake willof course increase as the s eed of the motor increases. sirabe to adjust its action so that it will not be applied until the motorsspeed begins to get too great. This may be done in any desired manner,as by means of a spring or by adding weight 116 to the core.

Fig. 2 illustrates a modification of this part It is deof my invention.In this case a relay 120 is provided. Its coil or solenoid-winding 121may be connected to the generator-mains 24 and 25 by conductors 24 25. Acore 122 is placed within this coil and is arranged to be drawn up bythe latter when it is sufficiently energized and to raise acontact-plate 123 up against two stationary contacts 124 and 125. Thebrake-magnet coil 111' may be in this case arranged to be connectedacross two of the mains from the outside source of supply. For example,conductors 32 and 33 may be connected to main-line conductors 32 and 33at any convenient lace. Conductor 32 is connected to one side of winding111, the otherside of which is connected to stationary contact 125,while conductor 33 is connected to stationary contact 124. Whencontactplate 123 is raisedu against contacts 124 and 125, a circuit wilbe completed thereby through brake-winding 111 and the brake will beapplied. In either case this brake may be arranged to retard the motorto its normal speed, or it may be arranged to have a greater effect,even to the extent of stopping the motor, if desired.

Above relay-core 122 I have shown a spring 126, with an ad'usting-screw127. These may be provided, if desired, to adjust the action of relay120 and cause it to act at any desired speed of motor 10.'

I have shown this invention as applied to an alternating-current motor;but it is not necessarily limited ,to this use. The invention is ofcourse applicable to many of the uses to which'electric motors may beput and is useful whenever it is desirable to control the movement ofthe motor either manually or electrically, or from a point near themotor, or from a distance, and also whenever it is desired to provide asimple and efficient means for automatically reventing the mofor fromattaining a speed in excess of a predetermined degree.

The brake herein described may of course be used in conjunction withother brakes, such as are well known,-for stopping the motor after thecurrent-supply has been cutoff from it.

What I claim is 1. The combination with a motor, of an acceleratingdevice therefor, a brake, an electric brake-applying means, a generatorconnected to said motor, and electric circuits and connections to effectthe operationof' said accelerating device immediately upon the startingof the motor and to effect the actuation of said brake-applying meansupon the motor attaining a predetermined speed.

2. The combination with a motor, of a starting device therefor, a brake,an electro-' magnet associated with said brake, a generator connected torun with the motor, and circuits and connections controlled by saidstarting device for effecting the operation of said electromagnet toapply the brake upon the motor attaining a pre etermined speed.

3. The combination with a motor, of a starting device therefor, agenerator connected to run with the motor, an electroma netic brake, andmeans controlled by sai starting device for effecting the opera tion ofsaid brake when the motor reaches a predetermined speed.

4. The combination with a motor, of starting apparatus therefor, agenerator to run with the motor, normally open switching mechanismcoacting with said starting apparatus, and an electromagnetic brakecontrolled by said switching mechanism.

5. The combination with a motor, of reversing switches therefor,'agenerator connected to said motor, a brake for said motor,electromagnetic means for positively applying said brake, and switchapparatus coacting' with said reversing-switches and connected betweenthe generator and the electromagnetic means to effect the operation ofthe brake upon the motor attaining a predetermined speed.

6. The combination with a motor, of reversing-switch apparatus therefor,a brake, an electric device for actuating said brake, a generator with anormally open circuit, and means actuated upon the operat1on of saidreversing-switch apparatus for closing the generator-circuit anelectrically connecting the same to said electric device.

7. The combination with a motor, of mainline and reversing-switches forsaid motor, a generator connected to be driven by said motor, a brakefor the motor, an electromagnet connected to said brake, acceleratingapparatus for the motor, an electromagnet for operating saidaccelerating apparatus, a normally open circuit includlng said generatorand said electromagnets, and electric switches connected to saidfirst-named switches for closing the circuit between said generator andthe brake and accelerating-magnets.

8. The combination with a motor, of a reversin -switch therefor, agenerator connecte to be driven by the motor, accelerating apparatus forthe motor, an electroresponsive device for operating said acceleratingapparatus, a normally 0 en circuit including the generator and saielectrorespon-.

sive device, a brake, a magnet for actuating said brake, said magnetbeing connected to said circuit, and means coacting with saidreversing-switch for changing the field connections of said generatorwhen the motor is reversed and for closing said normally open circuitwhen the reversing-switch is operated in either direction.

9.. The combination with a motor, of a re versin -switch. therefor, agenerator connected to e driven by the motor, a brake, anelectroresponsive device for operating said brake, a normally opencircuit including said means' coacting with" said reversing-switch forconnecting said generator to said electroresponsive device, and forchanging the field connections of-the is reversed. I

10: The combination with a'n alternatingcurrent motor; ofareversing-switchf therefor,

a dlrect-current generator connected to "run with! the motor,;-accelerating apparatu for the motor; anelectrorespansive device foroperating-said accelerating a 'aratu's, elc tromagnetic brake apparatusorthe-motor, a normall open circuit including said gen erator an sa1d.electroresponsive' device and electroma tic brake a am-mama auxillill'yswitc es= connectc to said reversing switch to effects reversal of thegeneratorfield connections when the motor is; reversed:

11. A motor; a reversing switch therefor, electrical means foractuatingsaid reversing,

switch, a bra-key agenerator connected to run wlththemotor; anelectroresponsive device" fore ratia "s'aid'brake, andmeans for comtrolling, sa1 e1ectroresponslve device to effect'theapplication of thebrake upon the g versing-switch' there or, abrake. ior the motor, adirect-current generator connected .to

run with the motor and arranged to actuate motorreaching-a=-predetermined speed-.

12-. A motor, a reversing switch therefor,- a rgenerator connected torun with the motor, said generator'h'a'vi'ng aseries field andbeingarranged to control-the acceleration ofth'e motor, andmeanscembi-ned with the reversin -switch for changing-the connections ofsaid series fields upon a reversalof themotor.

13. An altem'atin'g curren-t motor, a reversing switch therefor, adirect-current gen-' erator"connected'- tovwith the motor,- saidglenerator'having-an armature and a series eld and beingarran'gedtocontrol the acceleration 'of'the motor, and means combinedwith the reversing-switch for reversing the versi 4 actuating saidreversing-switch,-' a -direct=curconnections between sa'id v armature{and se-- rice field whenever the-reversing-switch is actuated to'reverse the motor. j

14-.- Art: 'alteriiatingacurrent'lmotor; a reversing switch therefor,means-q for actuati-ng said reversing switch a direct-current generatorconnected-to with the motor, said enera'tor 'having an armature and ase* ries eldfand: being-'- arranged" to control the acceleration-of themotor, and'means' combined with the =reversing-switch' for reversin Ithe connectionsbetween said armature an series field whenever 'thereversing-switch is actuated-to reverse the motor;

15.-'An alterfi'ati- '-current motor, aire' -swi-tch there or,electrical means for rent generator connected tor'u'nwi-th' the motor,saidgenerator having' -a- -series' field; a brake, a mzignetfor'actuating said brake, means for co'ntro'lling the acceleration of themotor, a-normally open circuit inchidin the brake-magnet, and meanscombined wit the reversing-switch for reversing theconnecgenerator-when' the motorse -94a" tio'ns'ofsaid series fieldwhenever the'said reversing-switch-is actuated to reverse the motorand-for closingsaid normally open aircuit. v I

16. An alternatin -current motor, a reversin -switch there or, electricmeans for operatmg said reversing-switch, a masterswitch for controllingsaidelectric means, a brake for the motor, an e'lectroresponsive devicefor operating said brake, and a directcurrentg'enerator connected to runwith the motor and to supply current'to-sa-id electroresponsive deviceto eflectthe application of I es a prede- 18. An alternatin-currentmotor, a rethe brake and to control theacceleration of themotor,said generator having an arma-.

ture' and a series field, and means combined withthe reversing-switchfor reversing the connections betweensaid armature andseries fieldwhenever the revers1ng-sw1tchis ac-' tuated to reverse the'motor.

19;, An altern'atin -cu -rrent motor, a re- 7 versing-switch there or,-a'brake for the mo-' tor, an opposition element inthe motor-circuit, adirect-current generator connected to run -with the motor and arrangedto actuate the'brake and to cutthe op ositionelement out of themotor-circuit, sai generator hav- 7 ing an armatureand a series field,and means on the reversing-switch for reversmg the connectrons" betweensa1darmature and series field whenever the reversing-switch is actuatedto reverse the motor. v

20. An altematin -current motor,-ja reversing-switch there or, a brakefor the motor, an opposition element in the motor-circuit, anda'direct-current generator connected" to rpn with the motor, saidgenerator being arranged 'to' generate a-current proporti'onal-instrength to the speed of the motor, and toactuatethebrakeandto cut theoppositionelement out of the motor-circuit as the motor'accelerat'es',said enerator having an armature andseries' fie d, and means combinedwith'the reversing-switch for'reversin the connections betweensaidarmature an series field whenever the series field is actuated toreverse the motor.

21. An alternatin -current motor, a reversing-switch there or means foractuati' rig the reversing-switch, a brake for the motor, an oppositionelement in the motor-circuit, a direct-current generator connected torun with the motor and arranged to generate a voltage proportional instrength to the speed of the motor, means dependent upon said variablevoltage for applying the brake to the motor, and electrorcsponsivedevice actuated by said variable voltage arrangedto cut' the oppositionelement out, of the motor-circuit ste by step in proportion to theacceleration o the motor; said direct-current generator having anarmature and a series field,

and means combined with the reversingswitch for reversing theconnections between 15 name to this specification in the presence of 2)two subscribing Witnesses.

' AXEL MAGNUSON.

Witnesses:

JOSEPH E. CAVANAUGH, ERNEST W. MARSHALL.

